Indicator device, measuring apparatus with indicator device and computer program product for evaluating the indicator device

Abstract

An indicator device represents a measured value and includes a first component and a second component. The first component includes a machine-readable first reference marker, a machine-readable second reference marker spaced from the first reference marker and a guide for the second component. The first reference marker defines a first reference point and the second reference marker defines a second reference point. The position and orientation of a predetermined path are defined by the first reference point and the second reference point. The second component can be positioned along the guide by a displacement force. The second component alone, or together with the first component, forms a machine-readable value indicator. The measured value is represented by a position of the value indicator along the predetermined path. The disclosure also relates to a measuring apparatus comprising the indicator device. The disclosure also relates to a computer program product for evaluating the indicator device of the measuring apparatus.

1 . An indicator device for representing a measured value, said indicator device comprising:
 a first component and a second component;   said second component being movable with respect to the first component, said first component including a machine-readable first reference marker, a machine-readable second reference marker spaced from the machine-readable first reference marker, and a guide for the second component;   wherein the machine-readable first reference marker defines a first reference point and the machine-readable second reference marker defines a second reference point, and wherein a position and orientation of a predetermined path are defined by the machine-readable first reference point and the machine-readable second reference point;   wherein the second component is positionable along the guide by a displacement force; and   wherein the second component alone, or along with the first component, forms a machine-readable value indicator, a position of the machine-readable value indicator along the predetermined path representing the measured value.   
     
     
         2 . The indicator device according to  claim 1 , wherein the machine-readable first reference marker, the machine-readable second reference marker, and/or the machine-readable value indicator each have at least two marker surfaces, or have four marker surfaces, and wherein the marker surfaces of the respective machine-readable first and/or second reference marker or machine-readable value indicator define a reference point. 
     
     
         3 . The indicator device according to  claim 2 , wherein at least two of the marker surfaces of the respective machine-readable first an/or second reference marker or machine value indicator each adjoin at least one other of the marker surfaces, a marker surface boundary being formed between two adjoining marker surfaces, and wherein the associated reference point is defined by a common intersection of at least two marker surface boundaries. 
     
     
         4 . The indicator device according to one of  claim 1 , wherein a machine-readable third reference marker with a third reference point is associated with the machine-readable first reference marker, and wherein the position and orientation of the predetermined path are defined by the first reference point together with the third reference point and the second reference point, optionally wherein a machine-readable fourth reference marker with a fourth reference point is associated with the machine-readable second reference marker, wherein in particular the position and orientation of the predetermined path is defined by the first reference point together with the third reference point and by the second reference point together with the fourth reference point. 
     
     
         5 . The indicator device according to one of  claim 1 , wherein the guide allows for a translational degree of freedom, and wherein the predetermined path and the translational degree of freedom of the guide are oriented substantially in parallel, alternatively wherein the guide allows for a rotational degree of freedom and wherein the predetermined path is arranged substantially along an arc around an axis of rotation of the rotational degree of freedom. 
     
     
         6 . The indicator device according to one of  claim 1 , wherein the guide allows for a translational degree of freedom and wherein the predetermined path and the translational degree of freedom of the guide are at an angle, in particular substantially perpendicular to each other. 
     
     
         7 . The indicator device according to  claim 6 , wherein the first component comprises a value indicator window, the value indicator window extending along the predetermined path at least in sections, wherein the second component comprises a indicator panel, the indicator panel having a first value indicator surface and a second value indicator surface, and wherein the first value indicator surface adjoins the second value indicator surface and forms an indicator surface boundary with the second value indicator surface in such a way that, when the indicator panel was positioned under the value indicator window by the displacement force during representation of a measured value, the indicator surface boundary meets the predetermined path and in particular an edge of the value indicator window at an angle, and wherein the position of the value indicator is defined by an intersection of the indicator surface boundary with the predetermined path. 
     
     
         8 . The indicator device according to  claim 7 , wherein the first component comprises a readiness indicator window, wherein the indicator panel has at least one first readiness indicator surface, wherein, in a zero position of the indicator device, the first readiness indicator surface is arranged under the readiness indicator window, in particular wherein the indicator panel includes a second readiness indicator surface, the second readiness indicator surface being formed and arranged such that the second readiness indicator surface is arranged under the readiness indicator window when the indicator device is not in the zero position. 
     
     
         9 . The indicator device according to  claim 1 , wherein the indicator device comprises a reset device configured to bring the second component into a zero position via a restoring force. 
     
     
         10 . The indicator device according to  claim 1 , wherein the first component and the second component are configured such that a displacement force and/or restoring force acting on the second component counteracts a holding force. 
     
     
         11 . A measuring apparatus comprising the indicator device according  claim 1 , in particular wherein the measuring apparatus is a peak flow meter. 
     
     
         12 . The measuring apparatus according to  claim 11 , wherein the measuring apparatus comprises an air inlet, an air outlet, and an air duct, the air duct extending from the air inlet to the air outlet, wherein a displaceable air resistance element is arranged in the air duct, and wherein the air resistance element is coupled with the second component of the indicator device in such a manner that, when the air resistance element is displaced, a displacement force can act on the second component in order to displace the second component. 
     
     
         13 . The measuring apparatus according to  claim 12 , wherein the air duct has a lateral opening, the air resistance element extending through the lateral opening into the air duct, and wherein the lateral opening is sealed by an elastic membrane, in particular wherein the elastic reduces the displacement force by an increasing reaction force with increasing displacement of the air resistance element. 
     
     
         14 . The measuring apparatus according to  claim 13 , wherein the measuring apparatus comprises an outer housing and an inner housing, wherein the outer housing, together with the inner housing, forms a hermetically sealed volume, and wherein the second component is arranged within the sealed volume; in particular wherein the outer housing has a recess for the air inlet, a recess for the air outlet, a recess for the first component of the indicator device, and optionally a recess for a reset device; in particular wherein the inner housing forms the air duct with the air inlet and the air outlet and includes the lateral opening for the air resistance element; in particular wherein the recesses in the outer housing, the lateral opening in the inner housing, and joints between the outer housing and the inner housing are hermetically sealed by seals. 
     
     
         15 . A computer program product for evaluating the indicator device of the measuring apparatus according to  claim 11 , in particular via a mobile terminal, configured to carry out the steps of:
 a) capturing a digital image of the indicator device with a camera,   b) evaluating the digital image to recognize the machine-readable first and second reference markers, in particular using edge recognition to recognize marker surface boundaries,   c) evaluating the digital image to determine the reference points of the respective machine-readable first and second reference markers,   d) determining the position and orientation of the predetermined path taking into account the determined first and second reference points,   e) evaluating the digital image to recognize and determine the machine-readable value indicator,   f) determining a position of the machine-readable value indicator along the predetermined path, in particular wherein the computer program product is further configured to carry out an optional step of:   g) correcting an optical distortion of the digital image taking into account at least first and second geometric pieces of information determined during evaluation of the digital image; in particular wherein the first geometric piece of information is a diameter, a height, or a width of the machine-readable first reference marker and correspondingly the second geometric piece of information is a diameter, a height, or a width of the machine-readable second reference marker, alternatively wherein the first geometric piece of information is a length and/or an orientation of a certain marker surface boundary of the machine-readable first reference marker and the second geometric piece of information is a length and/or an orientation of a corresponding marker surface boundary of the machine-readable second reference marker, alternatively wherein the first geometric piece of information is a distance or a vector between the first reference point and the third reference point and the second geometric piece of information is a distance or a vector between the second reference point and the fourth reference point.